Dual-axis MEMS gyroscope

Abstract

The present invention relates to a dual-axis MEMS gyroscope, comprising a substrate mechanism, an anchor mechanism, a motion mechanism, and an electrode mechanism. The anchor mechanism is fixedly mounted on the substrate mechanism. The motion mechanism comprises a drive frame, a mass unit, a commutation unit, a transmission unit, and a coupling unit. Four drive frames are evenly distributed around the center of the gyroscope, two of which are arranged at 45 degrees and the other two at 135 degrees. Four mass units are evenly distributed around the center of the gyroscope, two of which are arranged at 0 degrees and the other two at 90 degrees. The mass units comprise two mass modules arranged in sequence perpendicular to their respective directions, each comprising a Coriolis mass. The commutation unit comprises two lever components, and the transmission unit comprises two external transmission beams. The present invention can improve the robustness, angular vibration resistance, and overload resistance of the gyroscope, and reduce the inter-axis crosstalk of the gyroscope.

Description

Technical Field

[0001] The present invention relates to the field of detection technology, and in particular to a dual-axis MEMS gyroscope. Background Art

[0002] Gyroscopes, also known as angular rate sensors, are used to detect angular velocity around one or more axes. Gyroscopes developed using MEMS technology, particularly dual-axis MEMS gyroscopes, offer advantages such as high integration, compact size, and low cost. They have been widely used in consumer electronics, the automotive industry, and aerospace.

[0003] A typical dual-axis MEMS gyroscope is mainly a capacitive resonant gyroscope. Its basic working principle is that under the action of electrostatic force, the driving mass block drives the detection mass block to vibrate periodically through the first coupling spring. This mode is called driving motion or driving mode; when the external angular velocity is input, due to the action of Coriolis force, the detection mass block moves in a direction orthogonal to the driving motion, which is called detection motion or detection mode; the angular velocity can be obtained by detecting the capacitance change caused by the motion of the detection mass block.

[0004] Patent US11552006B2 discloses a dual-axis angular rate sensor that connects the drive modes of two sensing elements through a coupling structure. Only a single drive control circuit is required to drive the two axial sensing elements, which can reduce the package size and cost. However, the two axial sensing elements of this dual-axis angular rate sensor are independently distributed, resulting in large axial interference and common-mode interference in the sensing modes and poor accuracy. Patent CN107167123A discloses a micro-electromechanical two-axis gyroscope. This solution uses a rigid connection between four detection masses arranged in two sensing axes, resulting in large axial coupling and poor seismic resistance.

[0005] How to improve the robustness, anti-angular vibration and anti-overload performance of the dual-axis MEMS gyroscope and reduce the inter-axis crosstalk of the gyroscope is a technical problem that needs to be solved urgently in this field. Summary of the Invention

[0006] To this end, the present invention provides a dual-axis MEMS gyroscope, which can improve the robustness, anti-angular vibration and anti-overload performance of the gyroscope and reduce the inter-axis crosstalk of the gyroscope.

[0007] To solve the above technical problems, the present invention provides a dual-axis MEMS gyroscope, comprising a substrate mechanism, an anchor mechanism fixed to the substrate mechanism, a motion mechanism movably connected to the anchor mechanism, and an electrode mechanism for driving and detecting the motion mechanism, wherein the motion mechanism comprises:

[0008] Four drive frames are evenly distributed around the center of the gyroscope, with two drive frames symmetrically arranged at 45 degrees and the other two drive frames symmetrically arranged at 135 degrees. The drive frames are connected to the anchor mechanism via a first spring beam, and the drive frames have the freedom to reciprocate in the plane in which they are located;

[0009] Four mass units are evenly distributed around the center of the gyroscope, with two mass units symmetrically arranged in the 0-degree direction and the other two mass units symmetrically arranged in the 90-degree direction. The mass units include two mass modules arranged in sequence along a direction perpendicular to the direction in which they are located. The mass modules include mass blocks, each of which is connected to an anchor mechanism via a second spring beam. The mass blocks have the degrees of freedom to reciprocate in-plane about the z-axis, reciprocate out-of-plane about the x-axis, and reciprocate out-of-plane about the y-axis. The two mass modules of the same mass unit are connected by a first coupling spring arranged therebetween.

[0010] Four reversing units are respectively provided corresponding to the four drive frames. The reversing units include two levers, which are respectively provided on either side of the motion trajectory of the corresponding drive frame. The levers are connected to the anchor mechanism via a third spring beam. The levers have the freedom to reciprocate in the plane around the z-axis direction. One end of the lever is decoupled and connected to the corresponding drive frame.

[0011] Four transmission units are respectively arranged corresponding to the four mass units. The transmission units include two external transmission beams. The two external transmission beams are respectively arranged on the side of the two mass modules of the corresponding mass units facing away from the center of the gyroscope. The two external transmission beams of the same transmission unit are connected by a second coupling spring arranged between them. The second coupling spring is connected to the anchor point mechanism via a fourth spring beam. The external transmission beam has the freedom to reciprocate in a plane perpendicular to its direction. The external transmission beam is decoupled from the mass block on the center side of the gyroscope and the lever adjacent to it.

[0012] The coupling unit includes a coupling frame and a coupling ring. The coupling frame is arranged between the four mass units, and the coupling ring is nested in the coupling frame. The coupling frame is connected to the coupling ring via a fifth spring beam, and the coupling ring is connected to the anchor mechanism via a sixth spring beam. The coupling frame has a degree of freedom of rotation about the x-axis, and the coupling ring has a degree of freedom of rotation about the y-axis. The coupling frame decouples the four mass units.

[0013] Furthermore, the lever includes a first lever arm segment and a second lever arm segment connected at an angle to each other, the first lever arm segment is located on the side of the corresponding driving frame away from the mass unit, and the second lever arm segment is located on the side of the corresponding driving frame toward the mass unit, the intersection of the first lever arm segment and the second lever arm segment is connected to the third spring beam, the end of the first lever arm segment away from the third spring beam is connected to the end of the driving frame away from the center of the gyroscope through the first decoupling spring, the end of the second lever arm segment away from the third spring beam is connected to the adjacent external transfer beam through the second decoupling spring, and the external transfer beam is connected to the corresponding mass block through the third decoupling spring.

[0014] Furthermore, the two levers of the same reversing unit are connected to the corresponding driving frame via the same first decoupling spring.

[0015] Furthermore, the outer transfer beam extends in a direction perpendicular to the direction in which it is located, and one end of the outer transfer beam facing the lever is bent toward the side where the mass unit is located and then connected to the second decoupling spring.

[0016] Furthermore, the coupling unit also includes four internal transfer beams, which are respectively arranged corresponding to the four mass units. The internal transfer beams are arranged between the two mass modules of the corresponding mass units. The internal transfer beams extend along their directions. One end of the internal transfer beam is connected to the first coupling spring, and the other end of the internal transfer beam is connected to the coupling frame through the fourth decoupling spring.

[0017] Furthermore, each mass module includes two mass blocks arranged sequentially along the direction in which it is located, and the ends of the two mass blocks of the same mass module facing the same driving frame are connected by a third coupling spring.

[0018] Furthermore, ends of two mass modules of the same mass unit facing the coupling frame are connected via a fourth coupling spring, and the fourth coupling spring is connected to the coupling frame via a fifth decoupling spring.

[0019] Furthermore, the anchor point mechanism includes a first anchor point, a second anchor point, a third anchor point, a fourth anchor point, and a fifth anchor point;

[0020] The first spring beam is connected to the first anchor point, the second spring beam is connected to the second anchor point, the third spring beam is connected to the third anchor point, the fourth spring beam is connected to the fourth anchor point, and the sixth spring beam is connected to the fifth anchor point.

[0021] Furthermore, the electrode mechanism includes four first electrode units and four second electrode units. The four first electrode units are respectively arranged corresponding to the four driving frames. The first electrode unit includes a driving electrode and a driving detection electrode. The driving electrode is fixed on the substrate mechanism. The driving electrode drives the corresponding driving frame to reciprocate in the plane. The driving detection electrode is used to detect the motion amplitude, frequency and phase of the corresponding driving frame. The four second electrode units are respectively arranged corresponding to the four mass units. The second electrode unit includes a Coriolis force detection electrode, a Coriolis force feedback electrode and an orthogonal force correction electrode. The Coriolis force detection electrode is fixed on the substrate mechanism. The Coriolis force detection electrode detects the out-of-plane swing displacement of the corresponding mass block. The Coriolis force feedback electrode is used to start open-loop detection or closed-loop detection. A mass balance through-hole is provided on the mass block. The orthogonal force correction electrode and the mass balance through-hole constitute an orthogonal stiffness adjustment structure.

[0022] Furthermore, the substrate mechanism includes a first substrate and a second substrate arranged on one side of the first substrate in the z-axis direction. The anchor mechanism, the motion mechanism, and the first electrode unit are all connected to the side of the first substrate facing the second substrate, and the second electrode unit is arranged on the side of the second substrate facing the first substrate.

[0023] The above-mentioned technical solution of the present invention has the following advantages over the existing technology: the dual-axis MEMS gyroscope described in the present invention, on the one hand, connects different drive frames through the commutation unit and the transmission unit, thereby improving the synchronization, robustness and robustness of the drive modal motion of each axial direction; on the other hand, connects different mass units through the coupling unit, which can ensure that the mass blocks move with the same amplitude and frequency, effectively improving the detection accuracy of the Coriolis force signal, and can also eliminate the axial interference and common-mode interference between the mass blocks in different detection axes when the angular velocity is input, reduce the inter-axis coupling error, and improve the detection accuracy of each axis; moreover, the split support, coupling connection and differential detection scheme of multiple mass blocks can improve the overload resistance and signal-to-noise ratio of the gyroscope under the same volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings.

[0025] Figure 1 Schematic diagram of the structure of the dual-axis MEMS gyroscope in Example 1 of the present invention;

[0026] Figure 2 Schematic diagram of the connection of the driving frame of the dual-axis MEMS gyroscope in the first embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of the connection of the mass block of the dual-axis MEMS gyroscope in Example 1 of the present invention;

[0028] Figure 4Schematic diagram of the connection of the coupling unit of the dual-axis MEMS gyroscope in the first embodiment of the present invention;

[0029] Figure 5 This is a schematic diagram of the connection between the second spring beam and the second anchor point of the dual-axis MEMS gyroscope in Example 1 of the present invention;

[0030] Figure 6 Schematic diagram of a driving mode of the dual-axis MEMS gyroscope in the first embodiment of the present invention;

[0031] Figure 7 The dual-axis MEMS gyroscope in the first embodiment of the present invention is Figure 6 Schematic diagram of the detection mode around the y-axis under the driving mode;

[0032] Figure 8 The dual-axis MEMS gyroscope in the first embodiment of the present invention is Figure 6 Schematic diagram of the detection mode around the x-axis under the driving mode;

[0033] Figure 9 4 is a cross-sectional view of a mass unit of a dual-axis MEMS gyroscope in Example 1 of the present invention;

[0034] Figure 10 4 is a cross-sectional view of a mass unit of the dual-axis MEMS gyroscope in the detection mode in the first embodiment of the present invention;

[0035] Figure 11 Schematic diagram of a driving mode of the dual-axis MEMS gyroscope in the first embodiment of the present invention;

[0036] Figure 12 The dual-axis MEMS gyroscope in the first embodiment of the present invention is Figure 11 Schematic diagram of the detection mode around the y-axis under the driving mode;

[0037] Figure 13 The dual-axis MEMS gyroscope in the first embodiment of the present invention is Figure 11 Schematic diagram of the detection mode around the x-axis under the driving mode;

[0038] Figure 14 Schematic diagram of a driving mode of the dual-axis MEMS gyroscope in the first embodiment of the present invention;

[0039] Figure 15 The dual-axis MEMS gyroscope in the first embodiment of the present invention is Figure 14 Schematic diagram of the detection mode around the y-axis under the driving mode;

[0040] Figure 16 The dual-axis MEMS gyroscope in the first embodiment of the present invention is Figure 14 Schematic diagram of the detection mode around the x-axis under the driving mode;

[0041] Figure 17 Schematic diagram of the structure of the dual-axis MEMS gyroscope in the second embodiment of the present invention;

[0042] Figure 18 Schematic diagram of a driving mode of the dual-axis MEMS gyroscope in the second embodiment of the present invention;

[0043] Figure 19 The dual-axis MEMS gyroscope in the second embodiment of the present invention is Figure 18 Schematic diagram of the detection mode around the y-axis under the driving mode;

[0044] Figure 20 The dual-axis MEMS gyroscope in the second embodiment of the present invention is Figure 18 Schematic diagram of the detection mode around the x-axis under the driving mode;

[0045] Figure 21 Schematic diagram of a driving mode of the dual-axis MEMS gyroscope in the second embodiment of the present invention;

[0046] Figure 22 The dual-axis MEMS gyroscope in the second embodiment of the present invention is Figure 21 Schematic diagram of the detection mode around the y-axis under the driving mode;

[0047] Figure 23 The dual-axis MEMS gyroscope in the second embodiment of the present invention is Figure 21 Schematic diagram of the detection mode around the x-axis under the driving mode;

[0048] Figure 24 Schematic diagram of a driving mode of the dual-axis MEMS gyroscope in the second embodiment of the present invention;

[0049] Figure 25 The dual-axis MEMS gyroscope in the second embodiment of the present invention is Figure 24 Schematic diagram of the detection mode around the y-axis under the driving mode;

[0050] Figure 26 The dual-axis MEMS gyroscope in the second embodiment of the present invention is Figure 24 Schematic diagram of the detection mode around the x-axis under the driving mode;

[0051] Figure 27 Schematic diagram of the structure of the dual-axis MEMS gyroscope in the third embodiment of the present invention;

[0052] Figure 28 This is a connection diagram of the coupling unit of the dual-axis MEMS gyroscope in the third embodiment of the present invention;

[0053] Figure 29 Schematic diagram of the structure of the dual-axis MEMS gyroscope in the fourth embodiment of the present invention.

[0054] Description of the accompanying drawings:

[0055] 11. First substrate; 12. Second substrate;

[0056] 21. First anchor point; 22. Second anchor point; 23. Third anchor point; 24. Fourth anchor point; 25. Fifth anchor point;

[0057] 31. Drive frame; 32. Mass block; 321. Mass balance through hole; 33. Lever; 331. First lever segment; 332. Second lever segment; 34. External transfer beam; 35. Coupling frame; 36. Internal transfer beam; 37. Coupling ring;

[0058] 41. First spring beam; 42. Second spring beam; 43. Third spring beam; 44. Fourth spring beam; 45. Fifth spring beam; 46. Sixth spring beam;

[0059] 51. First coupling spring; 52. Second coupling spring; 53. Third coupling spring; 54. Fourth coupling spring;

[0060] 61. Driving electrode; 62. Coriolis force detection electrode; 63. Driving detection electrode; 64. Coriolis force feedback electrode; 65. Orthogonal force correction electrode;

[0061] 71. First decoupling spring; 72. Second decoupling spring; 73. Third decoupling spring; 74. Fourth decoupling spring. DETAILED DESCRIPTION

[0062] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0063] Example 1: See Figures 1 to 5 FIG. 1 shows an embodiment of a dual-axis MEMS gyroscope according to the present invention.

[0064] The dual-axis MEMS gyroscope includes:

[0065] substrate structure;

[0066] An anchor point mechanism, fixed on the substrate mechanism, including a first anchor point 21, a second anchor point 22, a third anchor point 23, a fourth anchor point 24 and a fifth anchor point 25;

[0067] The motion mechanism includes four drive frames 31, four mass units, four reversing units, four transmission units and a coupling unit. The four drive frames 31 are evenly distributed around the center of the gyroscope, two of which are located at 45 degrees, and the other two are located at 135 degrees. The drive frames 31 are connected to the first anchor point 21 through a first spring beam 41. The drive frames 31 have the freedom to reciprocate in the plane in the direction in which they are located. The four mass units are evenly distributed around the center of the gyroscope, two of which are located at 0 degrees, and the other two are located at 90 degrees. Upward, the mass unit includes two mass modules arranged in sequence along the vertical direction of the direction in which it is located, and the mass module includes a mass block 32. Each of the mass blocks 32 is connected to the second anchor point 22 through a second spring beam 42. The mass block 32 has the freedom to swing back and forth in the plane around the z-axis direction, out of the plane around the x-axis direction, and out of the plane around the y-axis direction. The two mass modules of the same mass unit are connected by a first coupling spring 51 arranged between the two. The four reversing units are respectively arranged corresponding to the four driving frames 31. The reversing unit includes two levers 33. The two levers 33 3 are respectively arranged on both sides of the motion trajectory of the corresponding driving frame 31, the lever 33 is connected to the third anchor point 23 through a third spring beam 43, the lever 33 has the freedom to swing back and forth in the plane around the z-axis direction, one end of the lever 33 is decoupled and connected to the corresponding driving frame 31, the four transmission units are respectively arranged corresponding to the four mass units, and the transmission unit includes two outer transmission beams 34, which are respectively arranged on the side of the two mass modules of the corresponding mass unit away from the center of the gyroscope, and the two outer transmission beams 34 of the same transmission unit are connected by a third spring beam 43 arranged between the two mass modules. The outer transfer beam 34 has a degree of freedom to reciprocate in a plane perpendicular to its direction. The outer transfer beam 34 is decoupled from the mass block 32 on the center side of the gyroscope and the lever 33 adjacent thereto. The coupling unit includes a coupling frame 35, which is arranged between the four mass units. The coupling frame 35 is connected to the coupling ring 37 via a fifth spring beam 45. The coupling ring 37 is connected to the fifth anchor point 25 via a sixth spring beam 46. The coupling frame 35 has a degree of freedom to rotate about the x-axis, and the coupling ring 37 has a degree of freedom to rotate about the y-axis. The coupling frame 35 is decoupled from the four mass units.

[0068] The electrode mechanism includes four first electrode units and four second electrode units. The above-mentioned four first electrode units are respectively arranged corresponding to the above-mentioned four driving frames 31. The above-mentioned first electrode unit includes a driving electrode 61. The above-mentioned driving electrode 61 is fixed on the above-mentioned substrate mechanism. The above-mentioned driving electrode 61 drives the corresponding above-mentioned driving frame 31 to reciprocate in the plane. The above-mentioned four second electrode units are respectively arranged corresponding to the above-mentioned four mass units. The above-mentioned second electrode unit includes a Coriolis force detection electrode 62. The above-mentioned Coriolis force detection electrode 62 is fixed on the above-mentioned substrate mechanism. The above-mentioned Coriolis force detection electrode 62 detects the out-of-plane swinging displacement of the corresponding above-mentioned mass block 32.

[0069] The 0-degree direction is parallel to the x-axis direction, and the 90-degree direction is parallel to the y-axis direction. The two mass units in the 0-degree direction detect the angular velocity in the y-axis direction, and the two mass units in the 90-degree direction detect the angular velocity in the x-axis direction.

[0070] The drive frame 31, mass 32, lever 33, external transfer beam 34, coupling frame 35, and coupling ring 37 are all rigid structures. The drive electrodes 61 receive drive signals from the peripheral circuitry and drive the corresponding drive frame 31 to perform in-plane reciprocating motion. The drive frame 31 drives the lever 33 to swing back and forth in the plane. The lever 33 drives the external transfer beam 34 to translate back and forth in the plane. The external transfer beam 34 drives the mass 32 to swing back and forth in the plane.

[0071] The structure and layout of the first spring beam 41 should ensure the freedom of each driving frame 31 to move along its own reciprocating direction and suppress movement in other directions. The structure and layout of the second spring beam 42 should ensure the freedom of the mass block 32 to swing around the set direction and suppress movement in other directions. The third spring beam 43 should ensure the freedom of the lever 33 to swing around the set direction and suppress movement in other directions. The structure and layout of the fourth spring beam 44 should ensure the freedom of the external transfer beam 34 to translate along the set direction and suppress movement in other directions. The structure and layout of the fifth spring beam 45 and the sixth spring beam 46 should ensure the freedom of the coupling frame 35 to swing along the set direction and suppress movement in other directions.

[0072] The lever 33 is decoupled from the driving frame 31 so that the motion modes of the two in different motion directions do not interfere with each other. The external transfer beam 34 is decoupled from the above-mentioned lever 33 so that the motion modes of the two in different motion directions do not interfere with each other. The mass block 32 is decoupled from the above-mentioned external transfer beam 34 so that the motion modes of the two in different directions do not interfere with each other. The coupling frame 35 is decoupled from the above-mentioned mass block 32 so that the motion modes of the two in different directions do not interfere with each other.

[0073] The provision of the first coupling spring 51 and the second coupling spring 52 can, on the one hand, effectively eliminate the coupling interference between the driving mode and the detection mode, and on the other hand, ensure that each mass block 32 moves with the same amplitude and frequency, thereby effectively improving the detection accuracy of the Coriolis force signal.

[0074] On the one hand, different drive frames are connected through the lever 33 and the external transfer beam 34 to improve the synchronization and robustness of the axial drive modal motion; on the other hand, different mass units are connected through the coupling frame 35. The coupling frame 35 can ensure that the mass blocks 32 move with the same amplitude and frequency, effectively improving the detection accuracy of the Coriolis force signal, and on the other hand, it can eliminate the axial interference and common-mode interference between the mass blocks 32 in different detection axes when the angular velocity is input, reduce the inter-axis coupling error, and improve the detection accuracy of each axis; moreover, the split support, coupling connection and differential detection scheme of multiple mass blocks 32 can improve the overload resistance and signal-to-noise ratio of the gyroscope under the same volume.

[0075] In this embodiment, each mass module includes a mass block 32 .

[0076] In this embodiment, the lever 33 includes a first lever segment 331 and a second lever segment 332 connected at an angle to each other. The first lever segment 331 is located on the side of the corresponding driving frame 31 away from the mass unit, and the second lever segment 332 is located on the side of the corresponding driving frame 31 toward the mass unit. The intersection of the first lever segment 331 and the second lever segment 332 is connected to the third spring beam 43. The end of the first lever segment 331 away from the third spring beam 43 is connected to the end of the driving frame 31 away from the center of the gyroscope through the first decoupling spring 71. The end of the second lever segment 332 away from the third spring beam 43 is connected to the adjacent outer transfer beam 34 through the second decoupling spring 72. The outer transfer beam 34 is connected to the corresponding mass block 32 through the third decoupling spring 73.

[0077] The length of the first lever arm section 331 is greater than that of the second lever arm section 332. The lever 33 has torque amplification and reversing functions, and can obtain a larger driving displacement using a smaller driving voltage, thereby reducing power consumption.

[0078] In this embodiment, the two levers 33 of the same reversing unit are connected to the corresponding driving frame 31 through the same first decoupling spring 71 .

[0079] On the one hand, the length of the first lever arm section 331 is longer, which saves more effort. On the other hand, the first lever arm sections 331 on both sides of the same driving frame 31 are close to each other, and the driving frame 31 can be connected by a first decoupling spring, saving the spring.

[0080] In this embodiment, the outer transfer beam 34 extends in a direction perpendicular to the direction in which it is located. One end of the outer transfer beam 34 facing the lever 33 is bent toward the side where the mass unit is located and then connected to the second decoupling spring 72 .

[0081] The direction of the outer transfer beam 34 is the line connecting the center of the outer transfer beam 34 and the center of the gyroscope. The outer transfer beam 34 is an L-shaped structure, which facilitates the connection between the outer transfer beam 34 and the lever 33.

[0082] In this embodiment, the above-mentioned coupling unit also includes four internal transfer beams 36, and the above-mentioned four internal transfer beams 36 are respectively arranged corresponding to the above-mentioned four mass units. The above-mentioned internal transfer beams 36 are arranged between the two mass modules of the corresponding above-mentioned mass units. The above-mentioned internal transfer beams 36 extend along the direction in which they are located. One end of the above-mentioned internal transfer beam 36 is connected to the above-mentioned first coupling spring 51, and the other end of the above-mentioned internal transfer beam 36 is connected to the above-mentioned coupling frame 35 through the fourth decoupling spring 74.

[0083] The direction of the inner transmission beam 36 is the line connecting the center of the inner transmission beam 36 and the center of the gyroscope.

[0084] In this embodiment, the first electrode unit further includes a driving detection electrode 63 . The driving detection electrode 63 is used to detect the corresponding movement amplitude, frequency and phase of the driving frame 31 .

[0085] The driving detection electrode 63 is used to detect the movement amplitude, frequency and phase of the driving part, and further acts on the driving part to perform frequency tuning through an external closed-loop control circuit.

[0086] In this embodiment, the second electrode unit further includes a Coriolis force feedback electrode 64 and an orthogonal force correction electrode 65. The Coriolis force feedback electrode 64 is used to enable open-loop detection or closed-loop detection. A mass balancing through-hole 321 is provided on the mass block 32. The orthogonal force correction electrode 65 and the mass balancing through-hole 321 constitute an orthogonal stiffness adjustment structure.

[0087] The orthogonal force correction electrode 65 is opposite to the mass balance through hole 321 . The orthogonal force correction electrode 65 generates corresponding electrostatic negative stiffness to offset the orthogonal stiffness introduced by the machining error, thereby achieving the purpose of orthogonal correction and improving the output accuracy of the gyroscope.

[0088] In this embodiment, the above-mentioned substrate mechanism includes a first substrate 11 and a second substrate 12 arranged on one side of the above-mentioned first substrate 11 in the z-axis direction. The above-mentioned anchor mechanism, the above-mentioned motion mechanism, and the above-mentioned first electrode unit are all connected to the side of the above-mentioned first substrate 11 facing the above-mentioned second substrate 12, and the above-mentioned second electrode unit is arranged on the side of the above-mentioned second substrate 12 facing the above-mentioned first substrate 11.

[0089] The working principle of this embodiment is described below.

[0090] See also Figure 6 As shown, a periodic drive voltage signal is applied to the drive electrode 61. Electrostatic forces cause the drive frame 31, arranged at 45° / 135°, to perform in-phase periodic reciprocating motion along the 45° / 135° direction. A compression or expansion power reversing mechanism converts the driving force or motion into reciprocating motion in the 0° / 90° direction. Specifically, the drive frame 31 drives the lever 33 to perform periodic, small rotations, which in turn drives the external transfer beam 34 to perform periodic, linear reciprocating motion. Ultimately, this drives the mass 32 to perform periodic, reciprocating in-plane oscillation, forming the drive mode of the gyroscope of the present invention.

[0091] See also Figure 7 As shown, when the angular velocity is input about the y-axis, the Coriolis force causes each mass block 32 to generate a periodic reciprocating motion in a direction perpendicular to its driving direction, that is, each mass block 32 performs an out-of-plane periodic reciprocating rotation, which is the motion mode of the gyroscope used for Y-axis angular velocity detection in the present invention. The input angular velocity about the x-axis can be obtained through the differential signal between the Coriolis force detection electrodes 62.

[0092] See also Figure 8 As shown, when the angular velocity is input about the x-axis, the Coriolis force causes each mass block 32 to generate a periodic reciprocating motion in a direction perpendicular to its driving direction, that is, each mass block 32 performs an out-of-plane periodic reciprocating rotation, which is the motion mode of the gyroscope used for X-axis angular velocity detection in the present invention. The input angular velocity about the x-axis can be obtained through the differential signal between the Coriolis force detection electrodes 62.

[0093] See also Figure 11 As shown, the driving frame 31 arranged at 45° / 135° direction performs anti-phase periodic reciprocating motion along the 45° / 135° direction, and converts the driving force or motion into reciprocating motion in the 0° / 90° direction through the extrusion or expansion power reversing mechanism;

[0094] See also Figure 12 and Figure 13 As shown, when the angular velocity is input about the y-axis or the x-axis, the Coriolis force causes the mass block 32 to perform an out-of-plane periodic reciprocating rotation.

[0095] See also Figure 14 As shown, the driving frame 31 arranged at 45° / 135° makes periodic reciprocating motion along the 45° / 135° direction as shown in the figure, and converts the driving force or motion into reciprocating motion in the 0° / 90° direction through the squeezing or expanding power reversing mechanism;

[0096] See also Figure 15 and Figure 16As shown, when the angular velocity is input about the y-axis or the x-axis, the Coriolis force causes the mass block 32 to perform an out-of-plane periodic reciprocating rotation.

[0097] Example 2: See Figure 17 As shown, the rest is the same as Example 1, except that each of the above-mentioned mass modules includes two above-mentioned mass blocks 32 arranged in sequence along the direction in which it is located, and the two mass blocks 32 of the same above-mentioned mass module are connected toward the ends of the same above-mentioned driving frame 31 through a third coupling spring 53.

[0098] Compared with the first embodiment, the difference between this embodiment lies in the number and connection method of the mass blocks 32. The mass blocks 32 of this embodiment adopt an array layout to increase the number of mass blocks 32. On the one hand, it increases the redundancy of the system and further improves the reliability of the maintenance system; on the other hand, it eliminates the inherent deviation and drift of the gyroscope and further improves the detection accuracy of the sensor.

[0099] See also Figure 18 As shown, a periodic drive voltage signal is applied to the drive electrode 61. Electrostatic forces cause the drive frame 31, arranged at 45° / 135°, to perform in-phase periodic reciprocating motion along the 45° / 135° direction. A compression or expansion power reversing mechanism converts the driving force or motion into reciprocating motion in the 0° / 90° direction. Specifically, the drive frame 31 drives the lever 33 to perform periodic, small rotations, which in turn drives the external transfer beam 34 to perform periodic, linear reciprocating motion. Ultimately, this drives the mass 32 to perform periodic, reciprocating in-plane oscillation, forming the drive mode of the gyroscope of the present invention.

[0100] See also Figure 19 As shown, when the angular velocity is input about the y-axis, the Coriolis force causes each mass block 32 to generate a periodic reciprocating motion in a direction perpendicular to its driving direction, that is, each mass block 32 performs an out-of-plane periodic reciprocating rotation, which is the motion mode of the gyroscope used for Y-axis angular velocity detection in the present invention. The input angular velocity about the x-axis can be obtained through the differential signal between the Coriolis force detection electrodes 62.

[0101] See also Figure 20 As shown, when the angular velocity is input about the x-axis, the Coriolis force causes each mass block 32 to generate a periodic reciprocating motion in a direction perpendicular to its driving direction, that is, each mass block 32 performs an out-of-plane periodic reciprocating rotation, which is the motion mode of the gyroscope used for X-axis angular velocity detection in the present invention. The input angular velocity about the x-axis can be obtained through the differential signal between the Coriolis force detection electrodes 62.

[0102] See also Figure 21As shown, the driving frame 31 arranged at 45° / 135° direction performs anti-phase periodic reciprocating motion along the 45° / 135° direction, and converts the driving force or motion into reciprocating motion in the 0° / 90° direction through the extrusion or expansion power reversing mechanism;

[0103] See also Figure 22 and Figure 23 As shown, when the angular velocity is input about the y-axis or the x-axis, the Coriolis force causes the mass block 32 to perform an out-of-plane periodic reciprocating rotation.

[0104] See also Figure 24 As shown, the driving frame 31 arranged at 45° / 135° makes periodic reciprocating motion along the 45° / 135° direction as shown in the figure, and converts the driving force or motion into reciprocating motion in the 0° / 90° direction through the squeezing or expanding power reversing mechanism;

[0105] See also Figure 25 and Figure 26 As shown, when the angular velocity is input about the y-axis or the x-axis, the Coriolis force causes the mass block 32 to perform an out-of-plane periodic reciprocating rotation.

[0106] Example 3: See Figure 27 and Figure 28 As shown, the rest is the same as the first embodiment, except that the above-mentioned internal transfer beam is not included, and the two mass modules of the same above-mentioned mass unit are connected toward the ends of the above-mentioned coupling frame 35 through a fourth coupling spring 54, and the fourth coupling spring 54 is connected to the above-mentioned coupling frame 35 through a fourth decoupling spring 74.

[0107] Compared with the first embodiment, the present embodiment reduces the coupling of the x- and y-axis masses and the inter-axis interference, so as to obtain a smaller cross-axis error, thereby improving the sensing performance of the sensor.

[0108] The driving mode and the detection mode of this embodiment are the same as those of the first embodiment.

[0109] Example 4: See Figure 29 As shown, the rest is the same as the second embodiment, except that the above-mentioned internal transfer beam is not included, and the two mass modules of the same above-mentioned mass unit are connected to the ends of the above-mentioned coupling frame 35 through the fourth coupling spring 54, and the fourth coupling spring 54 is connected to the above-mentioned coupling frame 35 through the fourth decoupling spring 74.

[0110] Compared with the second embodiment, this embodiment reduces the coupling and inter-axis interference of the x- and y-axis masses 32 to obtain a smaller cross-axis error, thereby improving the sensing performance of the sensor.

[0111] The driving mode and the detection mode of this embodiment are the same as those of the second embodiment.

[0112] In the detection mode diagram of this patent, the dot in the circle represents the in-plane swing of the mass block perpendicular to the paper surface, and the cross in the circle represents the out-of-plane swing of the mass block perpendicular to the paper surface.

[0113] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A dual-axis MEMS gyroscope, characterized in that: The invention comprises a substrate mechanism, an anchor mechanism fixed on the substrate mechanism, a motion mechanism movably connected to the anchor mechanism, and an electrode mechanism for driving and detecting the motion mechanism. The motion mechanism comprises: Four drive frames are evenly distributed around the center of the gyroscope, with two drive frames symmetrically arranged at 45 degrees and the other two drive frames symmetrically arranged at 135 degrees. The drive frames are connected to the anchor mechanism via a first spring beam, and the drive frames have the freedom to reciprocate in the plane in which they are located; Four mass units are evenly distributed around the center of the gyroscope, with two mass units symmetrically arranged in the 0-degree direction and the other two mass units symmetrically arranged in the 90-degree direction. The mass units include two mass modules arranged in sequence along a direction perpendicular to the direction in which they are located. The mass modules include mass blocks, each of which is connected to an anchor mechanism via a second spring beam. The mass blocks have the degrees of freedom to reciprocate in-plane about the z-axis, reciprocate out-of-plane about the x-axis, and reciprocate out-of-plane about the y-axis. The two mass modules of the same mass unit are connected by a first coupling spring arranged therebetween. Four reversing units are respectively arranged corresponding to the four driving frames, and the reversing units include two levers, which are respectively arranged on both sides of the motion trajectory of the corresponding driving frames. The levers are connected to the anchor mechanism through a third spring beam. The levers have the freedom to swing back and forth in the plane around the z-axis direction. One end of the lever is decoupled and connected to the corresponding driving frame. The lever includes a first lever arm segment and a second lever arm segment connected at an angle to each other. The first lever arm segment is located on the side of the corresponding driving frame away from the mass unit, and the second lever arm segment is located on the side of the corresponding driving frame toward the mass unit. The intersection of the first lever arm segment and the second lever arm segment is connected to the third spring beam. The end of the first lever arm segment away from the third spring beam is connected to the end of the driving frame away from the center of the gyroscope through a first decoupling spring. The end of the second lever arm segment away from the third spring beam is connected to the adjacent outer transfer beam through a second decoupling spring. The outer transfer beam is connected to the corresponding mass block through the third decoupling spring. Four transmission units are respectively arranged corresponding to the four mass units. The transmission units include two external transmission beams. The two external transmission beams are respectively arranged on the side of the two mass modules of the corresponding mass units facing away from the center of the gyroscope. The two external transmission beams of the same transmission unit are connected by a second coupling spring arranged between them. The second coupling spring is connected to the anchor point mechanism via a fourth spring beam. The external transmission beam has the freedom to reciprocate in a plane perpendicular to its direction. The external transmission beam is decoupled from the mass block on the center side of the gyroscope and the lever adjacent to it. The coupling unit includes a coupling frame and a coupling ring. The coupling frame is arranged between the four mass units, and the coupling ring is nested in the coupling frame. The coupling frame is connected to the coupling ring via a fifth spring beam, and the coupling ring is connected to the anchor mechanism via a sixth spring beam. The coupling frame has a degree of freedom of rotation about the x-axis, and the coupling ring has a degree of freedom of rotation about the y-axis. The coupling frame decouples the four mass units.

2. The dual-axis MEMS gyroscope according to claim 1, wherein: The two levers of the same reversing unit are connected to the corresponding driving frame via the same first decoupling spring.

3. The dual-axis MEMS gyroscope according to claim 1, wherein: The outer transfer beam extends in a direction perpendicular to the direction in which it is located. One end of the outer transfer beam facing the lever is bent toward the side where the mass unit is located and then connected to the second decoupling spring.

4. The dual-axis MEMS gyroscope according to claim 1, wherein: The coupling unit also includes four internal transfer beams, which are respectively arranged corresponding to the four mass units. The internal transfer beams are arranged between the two mass modules of the corresponding mass units. The internal transfer beams extend along their directions. One end of the internal transfer beam is connected to the first coupling spring, and the other end of the internal transfer beam is connected to the coupling frame through the fourth decoupling spring.

5. The dual-axis MEMS gyroscope according to claim 1, wherein: Each mass module includes two mass blocks arranged sequentially along the direction in which it is located, and the ends of the two mass blocks of the same mass module facing the same driving frame are connected by a third coupling spring.

6. The dual-axis MEMS gyroscope according to claim 1, wherein: Ends of two mass modules of the same mass unit facing the coupling frame are connected via a fourth coupling spring, and the fourth coupling spring is connected to the coupling frame via a fifth decoupling spring.

7. The dual-axis MEMS gyroscope according to claim 1, wherein: The anchor point mechanism includes a first anchor point, a second anchor point, a third anchor point, a fourth anchor point and a fifth anchor point; The first spring beam is connected to the first anchor point, the second spring beam is connected to the second anchor point, the third spring beam is connected to the third anchor point, the fourth spring beam is connected to the fourth anchor point, and the sixth spring beam is connected to the fifth anchor point.

8. The dual-axis MEMS gyroscope according to claim 1, wherein: The electrode mechanism includes four first electrode units and four second electrode units. The four first electrode units are respectively arranged corresponding to the four driving frames. The first electrode unit includes a driving electrode and a driving detection electrode. The driving electrode is fixed on the substrate mechanism. The driving electrode drives the corresponding driving frame to reciprocate in the plane. The driving detection electrode is used to detect the motion amplitude, frequency and phase of the corresponding driving frame. The four second electrode units are respectively arranged corresponding to the four mass units. The second electrode unit includes a Coriolis force detection electrode, a Coriolis force feedback electrode and an orthogonal force correction electrode. The Coriolis force detection electrode is fixed on the substrate mechanism. The Coriolis force detection electrode detects the out-of-plane swing displacement of the corresponding mass block. The Coriolis force feedback electrode is used to start open-loop detection or closed-loop detection. A mass balance through-hole is provided on the mass block. The orthogonal force correction electrode and the mass balance through-hole constitute an orthogonal stiffness adjustment structure.

9. The dual-axis MEMS gyroscope according to claim 8, characterized in that The substrate mechanism includes a first substrate and a second substrate arranged on one side of the first substrate in the z-axis direction. The anchor mechanism, the motion mechanism, and the first electrode unit are all connected to the side of the first substrate facing the second substrate. The second electrode unit is arranged on the side of the second substrate facing the first substrate.

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